1. Field of the Invention
This invention relates generally to optical lenses and, more particularly, to the fabrication of millimeter and sub-millimeter size optical lenses.
2. Description of the Related Art
There is a growing need for small size lenses. With each passing generation of cell phones, the number of cell phones with integrated cameras increases. The miniaturization that enables cell phone cameras has also given rise to other types of small cameras. The increasing number and variety of small cameras and other optical instruments results in an increasing demand for small size lenses.
As another example, ubiquitous sensor networks can enable global sensing by connecting numerous dispersed intelligent sensors that sense their local ambiance for changes in physical entities such as light, temperature, sound, and pressure. To be truly ubiquitous, these intelligent sensors must be compact and mass-producible at low cost. Sensing light, in particular, is useful for detecting illumination variations, capturing images, and for harnessing energy. Light sensors use optical lenses for efficient light collection. Small light sensors use small optical lenses.
Conventional techniques for fabricating miniature lenses, such as diamond turning, molding, lithography, and inkjet printing employ complex fabrication processes that are not inexpensively customizable. Thus, there is a need for miniature lenses, with millimeter or sub-millimeter sizes, that preferably can be customized and produced at a low cost.